The present invention relates generally to wear protective liners for the inner walls of chambers which are subjected to excessive wear forces and the invention is more particularly directed to a liner assembly for a blast chamber.
It has been known in the prior art to line the walls of blast chambers, for example centrifugal blast chambers, with a series of individual plates in order to protectively cover the blast chamber wall. These plates, which for the most part have a square shape, generally include an edge which is offset to about half the plate thickness and which forms with an adjacent plate a labyrinth packing consisting of inlet and outlet gaps extending perpendicularly to the plate, and of an interposed horizontal gap. A disadvantage of this type of protective lining involves the fact that this type of packing requires high accuracy with regard to the dimensions of the plates. In addition, most blasting media particles which impinge upon the plate can, with prior art arrangements, penetrate directly into the gap between the plates and it has been found that the kinetic energy of the particles within the gap is not reduced sufficiently such that the particles may be prevented from issuing through the second vertical gap on the other side of the plates. The blasting media particles impinging substantially vertically upon the chamber walls may therefore cause considerable damage to the walls and excessive wear. At the junction of four identically designed wear protective plates there is formed a direct uncovered blasting media passage so that the chamber walls will be subjected to excessive wear at these points as well.
A further effect which occurs is that upon the flat unreinforced blast protective plates there will occur sagging under the stress produced by the centrifugal jet thereby resulting in a harmful increase in the gap of the labyrinth packing.
One prior art arrangement known from U.S. Pat. No. 2,478,153 involves an arrangement wherein the wear protective plates are arranged in an overlapping fashion. However, in this type of arrangement no overlapping is provided between adjacent plates on two sides of the plate. As a result, the chamber wall is not protected against wear at these points or gaps. In addition, elaborate fastening means are required for the plates in this type of arrangement.
The present invention is directed toward the provision of a wear protective liner assembly composed of reinforced wear protective plates which form a labyrinth packing with each adjacent plate upon all the peripheral sides and corners of each plate, with the packing effect being to a great extent independent of the manufacturing or dimensional tolerances of the plates and of slight positional changes in the plates. Furthermore, the invention is directed toward an assembly which provides at the same time improved protection against wear of the chamber wall over presently known embodiments. The assembly of the present invention is such that it will permit easy removal and replacement of individual plates upon the chamber walls where they are mounted.